The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.
In general, a light-emitting diode (LED) is a light source having a very high speed of converting an electrical signal into light, e.g., about 30 ns to 250 ns, and may be rapidly switched on or off due to the above-described characteristics. As such, the LED is usable not only for lighting devices but also for visible light communication (VLC).
VLC is communication using visible light wavelengths (e.g., 380 nm to 780 nm), and data is transmitted and received by switching on or off photo diodes (PDs) included in an LED lamp.
Normally, when a light source flickers more than 100 times per second, human eyes do not recognize the flickering. Using the above principle of light, a VLC function may be performed in addition to a basic lighting function.